Structure characterization and thermophysical properties of R2LaTaO7 (R = Dy and Y) oxides

In the present work, the structure and thermophysical performances of Dy2LaTaO7 and Y2LaTaO7 were investigated. Analytical results show that Dy2LaTaO7 and Y2LaTaO7 exhibit single orthorhombic weberite structure. Because of the strong phonon scattering resulted by complicated structure, oxygen vacancies and doped atoms, their thermal conductivities are lower than value of Y2O3 stabilized ZrO2. The obtained compounds show that eminent phase stability is up to 1473 K. The heat expansion quotietis are also lower than value of Y2O3 stabilized ZrO2, and the lowest heat expansion quotiety of Y2LaTaO7 may be ascribed to the low ion size of Y3+ ions.